Lifting and transporting truck



Feb. 16, 1954 J. B. WILLIAMS LIFTING AND TRANSPORTING TRUCK Filed Oct.12, 1951 2 Sheets-Sheet 1i IIL Inventor John .Brynm or Williams A Home yFeb. 16, 1954 J. B. WILLIAMS 2,669,421

LIFTING AND TRANSPORTING TRUCK Filed Oct. 12, 1951 2 Sheets-Sheet 2Inventor John .Brynmor Williams I y 3% SPQMQTA, 23mm ttorney PatentedFeb. 16, 1954 LIFTING AND TRANSPORTING TRUCK John Brynmor Williams,Parbold, near Wigan, England, assignor to Ajax Trucks Limited,Manchester, England, a British company Application October 12, 1951,Serial No. 250,993

3 Claims.

This invention relates to that kind of lifting and transporting truckwherein the carrying platform is lifted by means of a lifting lever.

According to the said invention, a lifting and transporting truck of thehereinbefore specified kind has a link which is jointed by connectionsincluding a universal ball joint to the lifting 1ever and to a partconnected to or associated with the carrying platform, and operates totransmit motion from the lifting lever to the said part. The connectionspreferably also include an articulating joint of a different kind fromthe said universal ball joint.

The lifting lever is preferably operated by a handle lever adapted topush the lifting lever positively in the upward lifting direction butleave the lifting lever free to move independently of the handle leverin the return direction.

The lifting lever and handle lever are preferably arranged to swivelabout a vertical axis and be also capable of operation in the upwardlifting and return directions when in different angular positionsrelative to the said vertical axis, whereby the platform can be raisedand lowered and the truck can be pushed or pulled by the handle leverwhilst it is in different angular positions.

The lifting lever and handle lever are preferably both pivotally mountedto rotate about the same. axis, the lifting lever being accommodated bya gap in a forked end of the handle lever.

The link is preferably provided with a ball which engages a ball socketon the said part.

The link preferably has additionally a bearing provided in it andengaging a ball segment provided on the lifting lever.

Preferably, the link and the lifting lever cooperate, in the uppermostposition of the carrying platform, to produce a toggle action wherebythe carrying platform can be locked in a raised position.

A pedal or lever may be provided which when operated displaces the linkand lifting lever from the carrying platform locking position, andthereby causes them to cease to perform a toggle action.

The pedal or lever is preferably provided on the handle lever so that itbecomes operative only when the handle lever is in an out-of-useposition where it cannot be forced upwards by the descent of thecarrying platform and therefore cannot strike the operator.

A transmission member for transmitting motion. from the handle lever tothe lifting lever in the lifting direction only is preferably providedof the arrow shown in Figure 1; and

on the handle lever and is adapted to be shifted into an inoperativeposition by hand.

A locking device is preferably provided between the transmission memberand the handle lever for releasably locking the transmission member inan inoperative position.

A handle lever locking device is preferably provided for cooperationwith a bracket on the truck chassis frame for releasably locking thehandle lever in an out-of-use position.

In the accompanying drawings- Figure 1 is a fragmentary side elevationof a lifting and transporting truck;

Figure 2 is a detached side view illustrating a. detail, some of theparts being shown in different positions from thoseshown in Figure 1;

Figure 3 is an end view taken in the direction Figure 4. is a detachedend view, partly in section, illustrating a detail.

Referring to the drawings, in the construction shown therein, a truckchassis frame I having a pair of wheels 2 mounted on horizontal axles 3and a caster wheel 4, has pivoted on it two pairs of coupled bell-cranklevers one bell-crank lever of each pair being designated 5 and 6respectively. The bell-crank levers 5, 6 have pivotally mounted on thema platform frame 1. The platform frame I may, as shown in Figures 1 and3, carry a carrying platform 8, according to the purpose for which thetruck is intended, The

platform frame I has at one end, which terminates short of the casterwheel 4, an upwardly projecting part 9 having a horizontally extendingportion Hi.

The caster wheel 4 is mounted in a caster fork i I having a verticalofiset spigot I2 which is journalled in a ball bearing [3 provided inapart 14' of the truck chassis frame I. An upwardly projecting lug orbracket I4 is journalled on the part 44' of the truck chassis frame I torotate independently of the caster fork II. The lug I4 is connected bymeans of a pivot pin l5 to the forked lower end of a handle lever 15,the lug H extending into the gap between the prongs of the handle leverfork and being mounted on the pivot pin 5 to be rotatable independentlythereof. A

lifting lever l1 comprising two similar plates and therefore being adouble lever has its two plates extending between the prongs of thehandle lever 15 and has the lug l4 between its two plates. The liftinglever I! is mounted on the pivot pin i5. so that the lifting lever IT.can rotate independently of the pivot pin l5. The part M is a pivotingmeans common to the lifting lever l'l and the handle lever l8 and isalso a bearing for the lug ill by which the lifting lever 11 and handlelever 16 are rendered swivellable on the truck chassis about a verticalaxis. A lateral pin it is shiftably mounted on the handle lever l6 andis arranged to exert a rotative force on engagement thereof withshoulders IS on the plates of the lifting lever ll when the handle lever16 is rotated downwards on the pivot pin H in the platform frame liftingdirection, but to exert no rotative force on the lifting lever if whenrotated on the pivot pin in the return direction. The pin it istherefore a transmission member transmitting motion from the handlelever Hi to the lifting lever H. The pin I8 is connected to the ends ofthe arms of a hoop which is on the handle lever IE and can slidelongitudinally relative to the handle lever l6. Slots 2| are provided inthe handle lever it for the pin l8 which projects therethrough and canmove a distance in respect thereof sufdcient to allow the pin I8 to passout of register with shoulders 19 on the lifting lever 11 when the hoop2! is lifted. The hoop 20 has a handle portion 22 which can be hooked onto a projection 23 on the handle lever i 6 to hold the hoop 29 in itslifted position. The portion 22 and projection 23 together form alocking device for releasably locking the transmission member in aninoperative position. A pair of springs 24 is provided normally to urgethe hoop 20, when not hooked in its lifted position, into its lowermostposition wherein the pin i8 registers with the shoulders it on thelifting lever i1. By these means, the handle lever can be disengagedfrom the lifting lever and swung downwardly without raising the platform3.

The plates of the lifting lever H are secured together by a member whichhas a ball segment 25, namely a ball with fiat sides, and is attached tothe plates by means of opposed screwthreaded spigots 25 forming pivotstuds projecting from the sides of the ball segment 25 into holes in theplates and having securing nuts 2'! screwed on them. The ball segment 25is connected to the lower end of a link 28 by providing a bearing 29 inthe link, the surface of the bearing 29 being spherically curved and thebearing 29 having the ball segment 25 mounted in it so as to surroundthe ball segment 25, whereby the ball segment 25 is held againstseparation from the link 28. The bearing 29 and ball segment form anarticulating joint between the link 28 and the lifting lever 11. Thesaid joint transmits motion from the lifting lever I! to the part 9 bythe link 28 with a toggle action. The link 28 forms a tog le joint. ofthe bearing 29 is preferably porous oil impregnated metal.

The metal forming the bearing surface The link 23 extends upwards andits upper end is provided with a universal joint ball .30 by havingscrewed into a screwthreaded hole in its upper end, a screwthreadedspigot provided on V the ball 39. The ball 36 is connected to thehorizontally extending part ll) of the platform frame by beingpermanently mounted in. a ball socket 31 having a spigot 32 screwed intoa screw threaded hole in the part it and having a pad of bearing metal(not shown), preferably porous oil impregnated metal, with a sphericalbearing surface for the ball. The ball socket 3| and ball form auniversal ball joint and the ball 30 is held against separation from thesocket 3! by a cuff -33 screwed on to the socket 3i and having arestricted end orifice of less diameter than the ball 30.

A framework 34 attached to the truck chassis frame I forms an immovablebracket and has a catch recess 35 for co-operation with a handle leverlocking device comprising spring loaded catch 36 provided on the handlelever Hi to lock the handle lever It in an upstanding, out of useposition, the catch 36 being withdrawable against the action of thespring load by means of a hand operable handle '37 provided inside alarger stirrup-shaped part 38 of the handle lever I6.

The lifting lever IT has on each of its plates a shoulder 39 and theshoulders co-operate with stops 40 on the lug 14 to limit the pivotalmove-- ment of the lifting lever in the anti-clockwise direction so thatthe centre of the ball segment joint 25, 29 can be rotated into aposition beyond the point where it is in line with the centres of theball joint 39, 31 and the pivot l5 and be prevented by stops Ml andshoulders 39 from rotating beyond that position. In the said position,gravity operates to keep the parts in the said position and thereforethe platform remains in its up position. The dot-and-dash line 4|, 42makes clear it e locking condition.

To release the platform from its up position, the lever if and fink 23are displaced manually about their respective axes of rotation inclockwise direction until the centre of the ball segment joint 25, 29has moved beyond the said point, and

= thus enables gravity to continue movement of the said parts inclockwise direction and thereby allow the platform to sink into the downposition. Horizontal offsetting of the centres of the pivot 15 and theball joint 30, 3| as shown ensures the ability to move the parts intothe said position at will. a

In operation, when the handle lever 18 is in the locked position, theplatform frame 1 is in the down position. The handle lever I6 isreleased by operating the catch 36 by means of the handle 3'! and theplatform frame I is lifted by rotating the handle lever l6 about thepivot pin i5 whilst the hoop 28 is in the position shown in Figure 1relative to the handle lever H5. The pin l8 impinges against theprojections I9 on the lifting lever l1 and thereupon rotates the leveri! on the pivot pin (5 to force the link 28 upwards. The upwardly forcedlink 28 pushes the horizontally extending. part Ill of the platformframe I upwards and the platform frame 1 is thereby swung upwards on thebell-crank levers 5 and 6. The ball segment 25, hearing 29 and universalball joint 30, 31 by which the link 28 is connected to the lifting leverH and the platform frame I allow arcuate movements of the lifting leverand the different arcuate movement of the platform frame I to take placeirrespective of the momentary angular position 'of the handle lever! 6and lifting lever 11, about a vertical axis, whilst ensuring a strongsimple and enduring force-transmitting connection between the parts.

When the lifting platform is up it is locked temporarily in the upposition by the hereinbefore referred to toggle action and can beunlocked by the trip pedal 43. In order to guard against release of theplatform whilst the handle lever is in any other than an upstandingposition, with the consequent risk of the operator being struck underthe chin by the handle lever, the means consisting of the pedal 43cannot operate on the link 23 unless the handle lever is in a safeupstanding position.

The platform canbe made to descend slowly in known manner by dashpot orother means which form no part of this invention.

Iclaim:

1. A lifting and transporting truck comprising a truck chassis, acarrying platform movahly mounted on and supported b 3 voted link onsaid chassis for lifting with respect the an upwardly projecting partdirectly connected to said carrying platform one end thereof, a hallsocket provided on part at the end thereof, a call engaging socket, alink having said hall at one end, the said socket and ball forming auniversal ball joint between said part and said link, a lift leverprovided on the truck chassis in the vicinity of the said link forlifting said carrying hall segment on said li Ag lever, a hearingprovided at the other end of said link engaged by hall segment formingtherewith an articulating joint between said link and said lifting leverfor transmitting motion from said lifting lever to said part by linkwith a toggle action EJ115138 by the lifting lever and link support saidcarrying platform in a lifted position, a handle lever mounted on thetract; chassis for pushing said lifting lever positively in. the upwardlifting direction, a shoulder on the lifting lever, a transmissionmember shiitahly mounted on said handle lever and transmitting motionfrom said handle lever to said lifting lever lay engagement With saidshoulder in the platform lifting direction only whilst leaving saidlifting lever free for movement independently of handle lever in thereverse direction, a loc i handle lever for releasahly lo sion member inan inoperative position, an movable bracket provided on said chassis, ahandle lever locking device provided on the handle lever at its upperpart for locking said handle lever to said bracket in an out-of-useposition of said handle lever, a trip pedal rockalol mounted on saidhandle lever and situated in close proximity to the said lin: only whenthe handle lever is in its outf-use position, in which position of thehandle lever op eration of the trip pedal displaces said link and saidlifting lever from the position in which they support the carryingplatform in the lifted position and thereby cause the lifting lever andlink to cease to support the platform in the said position, pivotingrneans provided on the truck chassis and common to said lifting leverand said handle lever, a forked end provided on the handle lever andengaged by said lifting lever, and a bearing on the truck chassis bywhich said handle lever and said lifting lever are mounted swivellablyon truck chassis about a vertical axis.

2. A lifting and transporting truck comp-rising a truck chassis, a truckplatform liftably connected to the chassis by pivoted link means, atoggle joint operatively connected at its ends to the chassis andplatform for lifting the platform, a stop on the chassis which limitsthe extent of angular motion of the toggle joint for locking the saidjoint against further movement in one direction after it has passed itsstate of full extension, a lifting and hauling handle have con-- nectedto the chassis, a retractable pin on the er, a shoulder on the togglejoint enthe for operation of the toggle platfo m lifting direction, arockable lvct iy mounted on and participatnts and changes of position orrelative to the toggle joint, being located operativeiy close to onlywhen the handle lever is perative position and usable in that position,for joint in the platform by fcrcec impingement tthe saidtoggle joint.

3. A lilting transporting truclr comprising in combination, a chassis, aplatform liftably -mounted thereon oy pivoted link means, a bracketsecured to one end of the platform, a hall socket se to the upper end ofthe bracket, a ha l permanently mounted in the ball socket, a link ofwhich the upper end is formed by ball, a ng at the lower end of thelink, a bearing surface in the said hearing, hall permanently mounted inthe he ring, extending pivot studs on the lever is canted, a pivot pinon the t whereby e double lever is mounted on 1 a bearing on the chassisvhy the bracket is swivellahly mounted on re cha e? a handle levermounted on the said straddling the double lever and "ing to liftplatform and haul and push truck, a stirrup slidable on the handlelever, a catch pin secured to shiftable by the ""lilltip, the leverhaving slots for the catch pin to slide in laterally, a shoulder on thelever for transferring motion, when enicy said catch of the handle leverto the doc is lever in the platform lifting direction, stop on thebracket for limiting the extent of movement of the double lever in thesaid direction, a second houlder on the double lever co-operation withthe stop on the bracket, and means on the handle lever which can beoperated to trip the link only when the handle is in a positioncorresponding to the lowered position or the platform.

JOHN BRYNMOR WILLIAMS.

llteierences Cited in the file of this patent UNITED STATES PATENTS

